3 reasons why the Cardinals need to sign Jordan Walker to this extension right now
The club has clairty on future payroll commitments
As is the case with every offseason, the Cardinals have to weigh the cost of acquiring talent against current and future payroll commitments, something that becomes easier to do when you know what your long-term outlook is. If the Cardinals can lock up Walker long-term early, this would help them a ton in the team-building process.
At the moment, the Cardinals only have a few long-term deals on their roster. Nolan Arenado and Willson Contreras are locked up through 2028 and 2029 respectively, Paul Goldschmidt and Tyler O'Neill under locked up through 2025, while Steven Matz, Giovanny Gallegos, Tommy Edman, and Ryan Helsley are under contract through 2026. The only players out of that mix that are not facing arbitration are Contreras, Arenado, Goldschmidt, Matz, and Gallegos, so the numbers on the other guys' contracts are subject to chance.
For this Cardinal front office, it will be easier for them to make difficult decisions on those core players if they know where they stand with Walker. Giving a long-term deal out to guys like O'Neill, Hesley, or Edman, or even resigning Goldschmidt, are hard to plan for if a looming mega-deal for Walker is present.
Outside of resigning their own talent, the Cardinals will likely need to spend on rotation and possibly bullpen pieces in the next few seasons, which again, they will need to plan for how that impacts the rest of their roster.
Even if the Cardinals give Walker a significant extension now, they aren't "wasting" the years when they could have had him on a cheap deal. Here's a list of players who will be playing on bargain contracts over the next 3-8 years: Masyn Winn, Tink Hence, Gordon Graceffo, Brendan Donovan, Nolan Gorman, Dylan Carlson, Lars Nootbaar, Moises Gomez, Alec Burleson, Juan Yepez, and so many more. The Cardinals have the internal depth to afford to hand out big extensions, and they should take advantage of that with Walker.
There's one more reason I think the Cardinals should offer such an extension to Walker, and it may be the most important reason of all.